Gas exchange surfaces in both human lungs and plant leaves are highly adapted to maximize diffusion. Fick's Law of Diffusion mathematically describes this relationship as follows:
Rate of diffusion∝Surface Area×Concentration DifferenceThickness of Membrane \text{Rate of diffusion} \propto \frac{\text{Surface Area} \times \text{Concentration Difference}}{\text{Thickness of Membrane}} Rate of diffusion∝Thickness of MembraneSurface Area×Concentration DifferenceDescribe how the structural features of the human alveolus and surrounding capillary maximize the rate of diffusion in accordance with Fick's Law.
Describe how the structure of a plant leaf is adapted to maximize the rate of gas diffusion.
16 exam-style questions on Edexcel IGCSE Biology Gas exchange. Each one has a worked solution and a mark scheme showing where the marks go.